As energy costs continue to rise, coupled with a growing environmental awareness amongst the average consumer, an increasing interest in energy-saving methods has become apparent. To meet this interest, numerous energy services companies (ESCOs) offer potential clients plans for reducing energy-related costs in the home, office, factory, etc. For purposes of the following, an ESCO may also include a contractor or any other organization or individual that agrees to improve a structure. Many of these plans involve structural improvements being made to the building, and the costs of these improvements can be quite high. To provide an incentive for such capital improvements, ESCOs may agree to pay for the actual improvements in exchange for a portion of the resultant energy savings over a number of years.
Energy savings may be simply counted as: savings=(energy costs without the improvements)−(energy costs with the improvements). The first term of this energy-savings equation may be truly measured before the improvements are made to the structure, but thereafter becomes a hypothetical or simulated value. The second term may be hypothesized before the improvements are made, but thereafter becomes a real value that can be measured. The simple problem is, the two terms cannot both be measured as non-hypothetical values at the same time.
Because an accurate determination of the energy savings is essential to both the ESCO and the customer of the ESCO, a great deal of time and thought has gone into calculating the two terms in the savings equation. By way of example, U.S. Pat. No. 6,968,295 to Carr discloses a method and related system for auditing energy-usage at a facility, such as a grocery store. A plethora of data points concerning energy usage of the facility are identified, monitored and fed into a predictive algorithm running on a computer. The predictive algorithm is tuned until it outputs a computed energy-usage value that matches, within tolerable error, the measured energy-usage value of the facility. Thereafter, hypothetical changes to the facility may be fed into the model, which then outputs the expected energy savings from such changes. A drawback of the '295 patent, however, is that the value for the predicted energy-savings is only as good as the underlying predictive algorithm, and there is thus an inherent uncertainty as to whether actual energy savings will match the predicted value for those savings.
U.S. Pat. No. 5,717,609 to Packa et al. recognized this problem, and disclosed another method and related system to remedy it. The '609 patent discloses retrofitting a building, but leaving a small portion of the structure in its original state to provide the so-called baseline measurements, which are the measurements that provide the first term in the savings equation. Under the '609 patent, putative baseline measurements made with the small, unimproved portions of the structure could be had at the same time and under the same environmental conditions as their post-improvement counterparts. The '609 patent would thus appear to solve the dilemma of the energy-savings equation, allowing real (i.e., non-hypothetical), simultaneous measurements of both pre- and post-improvement parameters. However, it is believed that these small, unimproved portions do not, in fact, behave as they would if the entire structure were unimproved. Being surrounded by, and thermally interacting with, the improved portions of the structure, the unimproved portions do not mimic results that would be had from a fully unimproved structure. Hence, despite the appearance of accuracy, the baseline measurements obtained in the '609 patent are, in fact, incorrect. Additionally, customers generally do not like having one or more sections of their buildings being unimproved, but would rather that structure be improved in its entirety.